The present invention relates to a cassette seal for sealing off the gap between a bore hole and a shaft.
A known cassette seal is shown in U.K. Patent No. 881,607 having inner and outer rings of a comparatively complicated shape, which are secured inside one another. Limit-stop devices are provided in the inner and outer rings to simplify assembly. These limit stop devices are formed from rubber elastic material and are removed over time during normal use because of the relative movement between the inner and outer rings. The working properties of this known cassette seal are not satisfactory, the medium to be sealed off is not sufficiently recirculated in the direction of the space to be sealed off.
An object of the present invention is to provide a cassette seal that attains a considerably simplified and economic construction and assembly so that the seal comprises fewer individual parts to be secured inside one another. Another object of the present invention is to provide an improved cassette seal where the medium to be sealed off is better recirculated back into the space to be sealed off.